5‐(2‐Pyridyl)‐1,3‐di­thia­ne‐2‐thione

The title compound, C₉H₉NS₃, crystallizes with two mol­ecules in the asymmetric unit. In both mol­ecules, the di­thia­ne‐2‐thione rings adopt a symmetric half‐boat conformation with the C atom opposite the C—S_thione bond out of the plane. The pyridine ring is in an equatorial position and is twisted out of the plane of the half‐boat by 82.7 (2) and 84.5 (2)° in the two mol­ecules, so that the N atom is trans to the axial C—H bond in both cases.     

Two carbamoyl‐substituted di­hydro­pyrimidines: potential mimics of di­hydro­pyridine calcium channel blockers

The structures of two conformationally similar 1,4‐di­hydro­pyrimidines with a novel carbamoyl substitution, viz. 6‐methyl‐5‐(N‐methyl­carbamoyl)‐4‐phenyl‐1,2,3,4‐tetrahydro­py­rimidine‐2‐thione monohydrate, C₁₃H₁₅N₃OS·H₂O, (I), and 4‐(4‐chloro­phenyl)‐6‐methyl‐5‐(N‐methyl­carbamoyl)‐1,2,3,4‐tetra­hydro­pyrimidine‐2‐thione monohydrate, C₁₃H₁₄ClN₃OS·H₂O, (II), exhibit the structural features of 1,4‐di­hydro­pyridine calcium channel blockers. In both structures, the pyrimidine ring adopts a flattened boat conformation and the carbamoyl side chain is in an extended conformation with an anticlinal orientation. The phenyl ring occupies a pseudo‐axial position with respect to the pyrimidine ring in these structures. Both compounds crystallize with one mol­ecule of water, which participates in a two‐dimensional hydrogen‐bonding network. The mol­ecules are linked into dimers by N—H·S hydrogen bonds in both structures.     

Inclusion compounds of 2,5‐di­phenyl­hydro­quinone

The crystal structures of three 1:2 inclusion compounds that consist of host mol­ecule 2,5‐di­phenyl­hydro­quinone (C₁₈H₁₄O₂) and the guest mol­ecules 2‐pyridone (C₅H₅NO), 1,3‐di­phenyl‐2‐propen‐1‐one (chalcone, C₁₅H₁₂O) and 1‐(4‐meth­oxy­phenyl)‐3‐phenyl‐2‐propen‐1‐one (4′‐methoxy­chal­cone, C₁₆H₁₄O₂) were determined in order to study the ability of guest mol­ecules in inclusion compounds to undergo photoreaction. All of the crystals were found to be photoresistant. The three inclusion compounds crystallize in triclinic space group . In each case, the host/guest ratio is 1:2, with the host mol­ecules occupying crystallographic centers of symmetry and the guest mol­ecules occupying general positions. The guest mol­ecules in each of the inclusion compounds are linked to the host mol­ecules by hydrogen bonds. In the inclusion compound where the guest mol­ecule is pyridone, the host mol­ecule is disordered so that the hydroxy groups are distributed between two different sites, with occupancies of 0.738 (3) and 0.262 (3). The pyridone mol­ecules form dimers via N—H⋯O hydrogen bonds.     

Diethyl 4‐(2,5‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate,conformational change with solvent of crystallization

The title compound, C₂₁H₂₇NO₆, has been crystallized from ethanol containing nitro­benzene and shows the phenyl ring, B, in an ap conformation. This structure may be compared with that of the mol­ecule crystallized from ethanol alone, in which the B ring is seen in an sp conformation. The isolation of this rotamer has implications for the understanding of the docking of calcium beta‐blocking di­hydro­pyridine mol­ecules with their receptor site.     

3‐Methyl 5‐isopropyl 2‐methoxy­imino­methyl‐6‐methyl‐4‐(3‐nitro­phenyl)‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate

The crystal structure of the title compound, C₂₀H₂₃N₃O₇, consists of relatively isolated mol­ecules. The substituted 1,4‐di­hydro­pyridine ring adopts a flattened boat conformation. Both ester groups, at positions 3 and 5, have cis,cis geometry. The phenyl ring is nearly planar and is approximately perpendicular to the 1,4‐di­hydro­pyridine ring (dihedral angle 87.70°).     

(Z)‐7‐Chloro‐3‐[(3‐chloro­phenyl)­methyl­idene]‐4‐p‐tosyl‐3,4‐di­hydro‐2H‐1,4‐benzoxazine

In the title compound, C₂₂H₁₇Cl₂NO₃S, the mol­ecule is a substituted 3,4‐di­hydro‐2H‐1,4‐benzoxazine compound which has three phenyl rings which are essentially planar. The 3,4‐di­hydro‐2H‐oxazine part of the mol­ecule is fused to the benzo ring and has a half‐boat conformation; the dihedral angle between the planar part of the oxazine ring and the benzo ring is 10.2 (2)°. The (3‐chloro­phenyl)­methyl­idene substituent has a Z configuration in relation to the ring N atom of the oxazine moiety. Interestingly, the p‐toluenesulfonyl (p‐tosyl) substituent on the ring N atom protrudes away from the 3‐­chloro­phenyl substituent thus avoiding any steric interaction.     

3,5‐Di­amino‐6‐(2‐fluoro­phenyl)‐1,2,4‐triazine–di­methyl­form­amide (1/1)

The title compound, C₉H₈FN₅·C₃H₇NO, contains two independent complexes in the asymmetric unit, each consisting of one 3,5‐di­amino‐6‐(2‐fluoro­phenyl)‐1,2,4‐triazine mol­ecule and one di­methyl­form­amide solvent mol­ecule. One triazine mol­ecule is disordered over two conformations within the crystal, the occupancies being 62 (1) and 38 (1)%. The phenyl ring of this mol­ecule resolves into two conformations rotated by almost 180° about the bridging bond between the two rings, while the triazine rings approximately superimpose on each other. The triazine mol­ecules of the asymmetric unit differ in the dihedral angles between their respective phenyl and triazine ring planes, these being 57.6 (2)° for the fully occupied, and 76.9 (6) and 106.8 (8)° for the partially occupied mol­ecules. An extensive network of hydrogen bonds maintains the crystal structure.     

2‐(4‐Chloro­phenyl)‐1,3‐di­cyano‐6,7‐di­hydro‐4‐imino‐9,10‐di­methoxy­benzo­[a]­quinolizine–water (2/5)

Crystals of the title compound, C₂₃H₁₇ClN₄O₂·2.5H₂O, contain channels filled with highly disordered water mol­ecules. The best structure refinement was obtained by removing the solvent contribution from the intensity data and refining against a solvent‐free model. The central six‐membered ring of the quinolizine mol­ecule has a slightly distorted screw‐boat conformation.     

Two isomers of 2,4‐di­benzyl‐8‐azabicyclo­[3.2.1]­octan‐3‐ol

The crystal structures of the title compounds, 2α,4α‐di­benzyl‐3α‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3α‐ol), C₂₂H₂₇NO, (I), and 2α,4α‐di­benzyl‐3β‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3β‐ol), C₂₂H₂₇NO, (II), show that both compounds have a piperidine ring in a chair conformation and a pyrrolidine ring in an envelope conformation. Isomer (I) is asymmetric, the benzyl groups having different orientations, whereas isomer (II) is mirror symmetric, and the N and O atoms, the C atom attached to the hydroxy group, and the methyl C atom attached to the N atom lie on the mirror plane. In the crystal structures of both (I) and (II), the mol­ecules are linked together by intermolecular O—H⋯N hydrogen bonds to form chains that run parallel to the a direction in (I) and parallel to b in (II).     

Di­propyl 3,6‐di­phenyl‐1,2‐di­hydro‐1,2,4,5‐tetrazine‐1,2‐di­carboxyl­ate

The title compound, C₂₂H₂₄N₄O₄, was prepared from propyl chloro­formate and 3,6‐di­phenyl‐1,2‐di­hydro‐s‐tetrazine. This reaction yields the title compound rather than di­propyl 3,6‐di­phenyl‐1,4‐di­hydro‐s‐tetrazine‐1,4‐di­carboxyl­ate. The 2,3‐di­aza­buta­diene group in the central six‐membered ring is not planar; the C=N double‐bond length is 1.285 (2) Å, and the average N—N single‐bond length is 1.401 (3) Å, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie 0.3268 (17) Å from the plane of the ring. The mol­ecule has twofold crystallographic symmetry.     

(6R*,16R*)‐9,14‐Dihydro‐6‐methyl‐6,16‐methano‐6H,16H‐[2,4]benzothiazepino[3,4‐d][1,3,5]benzoxadiazocine hydrobromide dimethylformamide hemisolvate

The title compound, C₁₉H₁₉N₂OS⁺·Br^?·0.5C₃H₇NO, is an oxygen‐bridged phenyl­pyrimidine derivative in which the heterocyclic ring is protonated, the positive charge being dispersed over both of the N atoms. Both mol­ecules in the asymmetric unit exist in an identical conformation, which consists of a central planar portion with the two terminal phenyl rings protruding from the same side of the plane. One of the independent mol­ecules forms a strong hydrogen bond with the bromide anion, while the other is hydrogen bonded to the di­methyl­form­amide solvent mol­ecule.     

1,3‐Dibenzoylimidazolidine‐2‐thione and 1,3‐dibenzo­yl‐3,4,5,6‐tetra­hydro­pyrimidine‐2(1H)‐thione

The title compounds, 1,3‐dibenzo­ylimidazolidine‐2‐thione, C₁₇H₁₄N₂O₂S, (I), and 1,3‐dibenzo­yl‐3,4,5,6‐tetra­hydro­pyrimidine‐2(1H)‐thione, C₁₈H₁₆N₂O₂S, (II), were obtained from the reactions of imidazolidine‐2‐thione and 1,4,5,6‐tetra­hydro­pyrimidine‐2‐thiol, respectively, with benzoyl chloride. Compounds (I) and (II) contain, respectively, imidazolidinethione [C=S = 1.6509 (14) Å] and ­pyrimidinethione [C=S = 1.6918 (19) Å] moieties bonded to two benzoyl rings. The mol­ecules of (I) exhibit C₂ symmetry, the C=S bond lying along the twofold rotation axis, while the mol­ecules of (II) have mirror symmetry (C_s). The imida­zolidine ring in (I) is essentially planar, while the pyrimidine ring in (II) adopts a boat conformation. Mol­ecules of (I) are linked by weak inter­molecular C—H⋯O inter­actions, while mol­ecules of (II) are held together by van der Waals inter­actions.     

R(30) rectangular rings in 2,5‐dioxopiperazine‐1,4‐di­acetic acid

Molecules of the title 2,5‐dioxopiperazinedione derivative, C₈H₁₀N₂O₆, occupy centres of symmetry in the crystal structure. The six‐membered ring has an almost planar conformation, with the substituent on nitrogen nearly perpendicular to the ring. The ideal geometry of the isolated mol­ecule, as determined by ab initio HF–LCAO quantum‐mechanical calculations, is slightly more puckered than that observed in the solid state. In the crystal structure, a strong hydrogen bond joins neighbouring mol­ecules, thus forming a network of rectangular (30) rings.     

(5,11,17,23‐Tetra‐tert‐butyl‐26,28‐di­hydroxy­calix­[4]­arene‐25,27‐dioxy)­di­acetic acid N,N‐di­methyl­form­amide trisolvate

The title compound, C₄₈H₆₀O₈·3C₃H₇NO, is a derivative of calix­[4]­arene in the cone conformation, modified with distal carboxylic acid functional groups at the lower rim. A clathrate di­methyl­form­amide (DMF) mol­ecule is located within the calix­[4]­arene cone, and two DMF solvate mol­ecules participate in hydrogen bonding with the carboxylic acid groups. Intramolecular hydrogen bonds are also formed between the OH groups and the adjacent ether groups in the partially substituted calix­[4]­arene.     

1,3‐Thia­zolidine derivatives from regioselective [2+3]‐cyclo­additions of azomethine yl­ides with thio­ketones

The title compounds, namely di­methyl (2RS)‐2,3‐di­phenyl‐1,3‐thia­zolidine‐5‐spiro‐2′‐adam­antane‐4,4‐di­carboxyl­ate methanol sol­vate, C₂₈H₃₁NO₄S·0.275CH₄O, and di­methyl (4RS)‐3,4‐di­phenyl‐1,3‐thia­zolidine‐5‐spiro‐9′‐(9′H‐fluorene)‐2,2‐di­car­box­ylate, C₃₁H₂₅NO₄S, were obtained from dipolar [2+3]‐cyclo­additions of an azo­methine yl­ide with adamantane­thione and thio­fluorenone, respectively. The structures show that the choice of thio­ketone affects the regioselectivity of the cyclo­addition. The asymmetric unit of the former structure contains two mol­ecules of the thia­zolidine derivative plus a site for a partial occupancy (55%) methanol mol­ecule. O—H⋯O and C—H⋯O interactions link two of each of these entities into closed centrosymmetric hexamers. The five‐membered ring in each structure has an envelope conformation.     

4,1′,6′‐Trichloro‐4,1′,6′‐trideoxysucrose monohydrate

At 160 K, the gluco­pyran­osyl ring in 1,6‐di­chloro‐1,6‐di­deoxy‐β‐d ‐fructo­furan­osyl 4‐chloro‐4‐deoxy‐α‐d ‐gluco­pyran­oside monohydrate, C₁₂H₁₉Cl₃O₈·H₂O, has a near ideal ⁴C₁ chair conformation, while the fructo­furan­osyl ring has a ⁴T₃ conformation. The conformation of the sugar mol­ecule is quite different to that of sucralose, particularly in the conformation about the glycosidic linkage, which affects the observed pattern of intramolecular hydrogen bonds. A complex series of intermolecular hydrogen bonds links the sugar and water mol­ecules into an infinite three‐dimensional framework.     

tert‐Butyl (3S,6R,9R)‐(5‐oxo‐3‐{[1(R)‐phenyl­ethyl]­carbamoyl}‐1,2,3,5,6,7,8,8a‐octa­hydro­indolizin‐6‐yl)­carbamate monohydrate at 95 K

The asymmetric unit of the title compound, C₂₂H₃₁N₃O₄·H₂O, incorporates one water mol­ecule, which is hydrogen bonded to the 3‐oxo O atom of the indolizidinone system. The two rings of the peptidomimetic mol­ecule are trans‐fused, with the six‐membered ring having a slightly distorted half‐chair conformation and the five‐membered ring having a perfect envelope conformation. The structure is stabilized by intermolecular O—H?O interactions between the water and adjacent peptide mol­ecules, and by N—H?O interactions between the peptide mol­ecules, which link the mol­ecules into infinite chains.     

Di­spiro­[fluorene‐9,5′‐[1,2,3,4]­tetra­thia­ne‐6′,9′′‐fluorene]

The tetra­thia­ne ring of the title compound, C₂₆H₁₆S₄, has a chair conformation and the mol­ecule has approximate C₂ symmetry. Each of the two fluorene ring systems is virtually planar, with the ring planes intersecting at an angle of 67.58 (5)°. This novel compound has been formed as a side product from the treatment of 9H‐fluorene‐9‐thione with methyl N‐[(benzyl­idene)­phenyl]­glycinate in the presence of LiBr and 1,6‐di­aza­bi­cyclo­[5.4.0]­un­decane.     

The dimer,trimer and 1,2,4‐tri­thiol­ane of adamantane­thione

The mol­ecules of di­spiro­[1,3‐dithietane‐2,2′:4,2′′‐diadamantane], C₂₀H₂₈S₂, have crystallographic C_i symmetry, as well as local D_2h symmetry, and a planar 1,3‐dithietane ring. The mol­ecules of tri­spiro­[1,3,5‐tri­thia­ne‐2,2′:4,2′′:6,2′′′‐triadamantane], C₃₀H₄₂S₃, have approximate C₂ symmetry and the 1,3,5‐tri­thia­ne ring has a twist–boat conformation. The C—S—C bond angles within the ring are about 8° larger than observed in most related 1,3,5‐tri­thia­ne structures. In di­spiro­[1,2,4‐tri­thiol­ane‐3,2′:5,2′′‐diadamantane], C₂₀H₂₈S₃, the mol­ecules have local C₂ symmetry and the 1,2,4‐tri­thiol­ane ring has a half‐chair conformation.     

1‐(1,3‐Di­thian‐2‐yl)‐2‐phenyl­ethanone

The title mol­ecule, C₁₂H₁₄OS₂, has approximate C_s symmetry. The di­thia­ne ring adopts a chair conformation with the acetyl substituent in an axial orientation. Weak intermolecular C—H?O hydrogen bonds link mol­ecules into a chain along the y axis.